This invention pertains to apparatus for converting signals representing trigonometric functions of angles to coded combinations of binary signals representing the angles.
In measuring the frequency of microwave signals, or the bearing angle of incoming radar signals, or the polarization of such signals, as well as phase differences, correlators are used. The outputs of the correlators are generally signals which are sine and cosine functions of a phase angle. At first these signals were displayed on a calibrated CRT display. As time progressed much greater accuracies were required.
The art started to move toward digital techniques. Typical devices as analog signal processors are shown in U.S. Pat. No. 3,800,221 issued Mar. 26, 1974. These signal processors while they satisfied the need were complex and cumbersome and created the demand for even better digitizers.